The present invention relates to a bone tunnel forming method and a bone-excavating apparatus for repairing a ligament which is used to form a bone tunnel for introducing a repairing ligament which is to be transplanted thereinto in a ligament-repairing operation such as a posterior cruciate ligament-repairing operation.
In the posterior cruciate ligament-repairing operation, to implant a repairing ligament, for example, an artificial ligament on an articulation, a first bone hole is formed into the tibia and a second bone tunnel is formed into the femur. Then, the artificial ligament is implanted on the articulation by penetrating artificial ligament into the two bone tunnels. Thereafter, the ligament is fixed to a position proximately to an opening of the bone hole formed in the tibia and to an opening of the bone hole formed into the femur.
In this method, it is necessary to form the bone tunnel having almost the same inner diameter from the tibia side to the femur side. Thus, in carrying out an autotransplantation of a ligament, a large amount of a normal part of the tibia is taken out, which causes a large quantity of surgical invasion to be made on the normal part of the ligament. Further, a large amount of bone is lost in the articulation, which causes the bone to be weak. In addition, because it is necessary to cut off a large amount of bone, it takes much time and labor.